JP2009014660A - Two-liquid leakage sensor and prism for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-liquid leakage sensor using a prism for detecting kinds and existence of liquid for water and oil etc., separately, excellent in safety and simple in configuration and capable of manufacturing at a low cost using a prism having a refraction index same as that of the detecting liquid or approximately same as that of the detection liquid. <P>SOLUTION: The two-liquid leakage sensor includes: a light emitter for irradiation with the light, a first optical fiber for guiding the light to the light emitter, and the prism provided with a light incident surface and a light exit surface, where the light enters an incident surface and out going from an exit surface, first and second light receiving parts arranged on the two places for receiving the light out going from the exit surfaces, the first and the second light receiving parts for receiving the light introduced by second and third optical fibers. According to the existence of the light receiving, or the light receiving amount by the first and the second light receivers, existence of leakage liquid soaking the prism and whether the leakage liquid is the prescribed liquid or not is informed of. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a two-liquid leakage sensor for detecting leakage by distinguishing between liquid types such as water and oil, and a prism for the same, and more particularly to leakage due to the difference in the refractive index of light at the interface between the prism and the liquid to be detected. The present invention relates to a two-leakage sensor that distinguishes between different types of liquid crystal and a prism therefor.

  In facilities such as conventional factories, liquid is supplied by piping. Since pipes are provided with joints for connection at many locations, liquid often leaks from the joints. Depending on the type of liquid, a human must always monitor the leakage, but a leakage sensor that automatically detects and notifies the leakage has been developed. Conventionally used leakage sensors for monitoring leakage include an optical leakage sensor, a leakage sensor using a magnetic sensor, a continuity leakage sensor, and a capacitance leakage sensor. is there.

  For example, Japanese Patent Laying-Open No. 2005-140635 (Patent Document 1) discloses an optical liquid leakage sensor 200 as shown in FIGS. In the liquid leakage sensor 200, a triangular prism 202 is formed on a circular case body 202 made of a transparent synthetic resin material and protrudes downward substantially at the center of the bottom surface. Two pairs of integrated light emitting elements 207A and 207B and light receiving elements 208A and 208B using a photo interrupter 206 capable of emitting and receiving light from different directions via the prism 201 are supported by the case body 202 by the element housing recess 203 and the support base 204. It is attached to the board | substrate 205 provided so that it might be. A cord insertion hole is provided in the outer peripheral portion 202 a of the case body 102, and the opening 202 b of the case body 202 is covered with a lid 211.

  The liquid leakage sensor 200 is attached to a bottom surface 212 on a mounting plate 213 that is bolt-fixed, weld-fixed, or adhesively fixed via a mounting piece 214 that can be attached to and detached from a mounting hole 209 of the mounting portion 210, and the lower end portion of the prism 201 is the floor It is set so as to be located in the vicinity of the surface 212.

  In this state, the irradiation lights X and Y from the light emitting elements 207A and 207B are reflected by the prism 201 and received by the light receiving elements 208A and 208B, respectively, as shown in FIG.

  When leakage occurs, the prism 201 is immersed in the leakage and does not function as a prism. Therefore, the irradiation lights X and Y from the light emitting elements 207A and 207B are not received or attenuated by the light receiving elements 208A and 208B. Thus, leakage can be detected.

  A magnetic leak sensor 310 using a magnetic sensor as shown in FIG. 27 is known as a device for alarming when water enters a tank storing oil such as gasoline or petroleum. The magnetic leak sensor 310 includes a doughnut-shaped float 312 to which a magnet 311 is attached, a magnetic sensor 313 that detects a magnetic field formed by the magnet 311, and a magnetic sensor 313, and a lift guide for the float 312. It is comprised with the column-shaped guide member 314 which has a function of a stick | rod. The magnetic sensor 313 in the guide member 314 is disposed at the bottom of the tank 301 in which the oil 302 is stored, the specific gravity of the float 312 to which the magnet 311 is attached is greater than the specific gravity of the oil 302, and the specific gravity of water. Make it smaller.

Thus, when water does not enter the tank 301, the float 312 with the magnet 311 attached sinks into the oil 302 and is positioned at the bottom of the tank 301, and the magnetic sensor 313 detects the magnetic field by the magnet 311. Is done. On the other hand, when water enters the tank 301, the water has a specific gravity greater than that of the oil, so that the water accumulates at the bottom of the tank, and the float 312 with the magnet 311 attached rises to the water. For this reason, the magnetic field detected by the magnetic sensor 313 becomes small or no magnetic field is detected, and it can be detected and notified that water has entered the tank 301.
JP 2005-140635 A JP 2001-74589 A

  The optical leak sensor described in Patent Document 1, the conductive leak sensor, and the capacitive leak sensor all detect only the presence or absence of leaks, such as water and oil. It does not detect the type of leakage. Especially in gas stations and food plants, in order to detect water that has entered the tank that stores oil such as gasoline and oil, and to detect oil that has entered the tank that stores water, The emergence of a two-liquid leak sensor that can detect leaks by distinguishing types is strongly desired.

  The optical leak sensor described above uses a prism, but it is convenient to have the same or similar refractive index as the liquid detected by the prism when distinguishing the type of liquid. However, it is difficult for a conventional prism manufactured only from a transparent or translucent material to have a refractive index that is the same as or close to that of the liquid for detecting the refractive index of the prism.

  Moreover, since the magnetic leak sensor using the above-mentioned magnetic sensor needs to install an electric system in the guide member, there is a need for explosion prevention. Therefore, it is hoped that a two-liquid leakage sensor that has a safer and simpler configuration and that can be manufactured at low cost, does not need to install an electrical system in a portion that may be in contact with the leakage. It is rare.

  The present invention has been made under the circumstances as described above, and the object of the present invention is to detect the type of liquid such as water and oil and the presence or absence of the liquid, and is excellent in safety and from a simple configuration. An object of the present invention is to provide a two-liquid leakage sensor that can be manufactured at low cost and a prism therefor.

  The present invention relates to a two-liquid leak sensor that detects a leak by distinguishing between liquid types, a light emitter that is driven by a light emission drive unit to irradiate light, a first optical fiber that guides the light to the light emission unit, and A prism having an incident surface on which light from the light emitting unit is incident and an emission surface from which light incident from the incident surface is emitted, and a first light receiving element disposed at two locations for receiving the light emitted from the emission surface And a second light receiving unit, a first light receiver that receives light guided from the first light receiving unit to the second optical fiber, and a light guided from the second light receiving unit to the third optical fiber. The presence or absence or amount of light received by the second light receiver, the first light receiver and the second light receiver is detected, and the presence or absence of the liquid immersing the prism and whether or not the liquid leakage is a predetermined liquid. A light receiving processing unit for determining whether the first light receiving unit is The second light receiving unit is configured to receive light emitted from the prism when the prism is not immersed in liquid leakage. A two-liquid leakage liquid that is arranged to receive light, the prism is formed of a transparent or translucent hollow member, and the liquid or jelly-like substance and the liquid or jelly-like substance are enclosed in the hollow member This is achieved by a sensor or when the liquid sealed in the hollow member is water, and the liquid sealed in the hollow member is oil.

  The present invention relates to a two-liquid leak sensor that detects a leak by distinguishing between liquid types, a light emitter that is driven by a light emission drive unit to irradiate light, a first optical fiber that guides the light to the light emission unit, and A prism having an incident surface on which light from the light emitting unit is incident and an emission surface from which light incident from the incident surface is emitted; and a first light receiving unit disposed at three locations for receiving the light emitted from the emission surface , A second light receiving portion and a third light receiving portion, a first light receiving device for receiving light guided from the first light receiving portion to the second optical fiber, and a light guide guided from the second light receiving portion to the third optical fiber. A second light receiving device for receiving the light, a third light receiving device for receiving the light guided from the third light receiving portion to the fourth optical fiber, the first light receiving device, the second light receiving device, and the third light receiving device. The prism is immersed by detecting the amount of light received or the amount of light received by the receiver. A first light receiving unit configured to receive the light emitted from the prism when the liquid immersed in the prism is oil. And the second light receiving unit is arranged to receive light emitted from the prism when the liquid in which the prism is immersed is water, and the third light receiving unit is configured to prevent the prism from leaking. A two-liquid leakage sensor that is disposed so as to receive light emitted from the prism when not immersed, is composed of a transparent or translucent hollow member, and oil is sealed in the hollow member. Achieved.

  The present invention relates to a two-liquid leak sensor for detecting water that enters a tank that stores oil, a light emitter that is driven by a light emission drive unit to emit light, and a first light that guides the light to the light emission unit. A prism having a fiber, an incident surface on which light from the light emitting unit is incident, and an emission surface from which light incident from the incident surface is emitted, and a light receiving unit disposed to receive the light emitted from the emission surface And a light receiver that receives light guided to the second optical fiber from the light receiver, and the liquid in which the prism is immersed is oil or water depending on whether or not the light is received by the light receiver A light receiving processing unit for determining whether the light emitting unit, the prism, and the light receiving unit are disposed in a case, and the case is disposed at a bottom portion of the tank. Is a transparent or translucent hollow Or a two-liquid leakage sensor in which oil or water is enclosed in the hollow member, or the case is attached to a cylinder attached to a lid member of the tank, and the case is To the bottom of the tank.

  The present invention relates to a two-liquid leakage sensor for detecting oil entering a tank that stores water, a light emitter that is driven by a light emission drive unit to irradiate light, and a first light that guides the light to the light emission unit. A fiber, a prism having an incident surface on which light from the light emitting unit is incident, an emission surface from which light incident from the incident surface is emitted, and a light receiving unit disposed to receive the light emitted from the emission surface And a light receiver that receives light guided to the second optical fiber from the light receiving unit, and whether the liquid in which the prism is immersed is oil or water depending on whether or not the light is received by the light receiver A light-receiving processing unit for determining, wherein the prism is formed of a transparent or translucent hollow member, and oil or water is sealed in the hollow member, and the light-emitting unit, the prism, and the light-receiving unit are provided with a holder. To the float via Is, the float is achieved by 2 Ekimoeki sensor the prism is so immersed in the oil when the oil has penetrated into the tank.

  The present invention relates to a two-liquid leak sensor that detects a leak by distinguishing between liquid types, a light emitter that is driven by a light emission drive unit to irradiate light, a first optical fiber that guides the light to the light emission unit, and A prism having an incident surface on which light from a light emitting unit is incident and an output surface from which light incident from the incident surface is emitted, a reflecting mirror that reflects light emitted from the emitting surface, and light reflected by the reflecting mirror A light receiving unit disposed adjacent to or close to the light emitting unit on the same side as the light emitting unit, and a light receiver that receives light guided from the light receiving unit to the second optical fiber, A light receiving processing unit that determines whether or not the liquid in which the prism is immersed is a predetermined liquid according to the presence or absence of light received by the light receiver or the amount of light received, the light emitting unit, the prism, the reflecting mirror, The light-receiving unit has the prism When the liquid is a predetermined liquid, the light irradiated from the light emitting unit is arranged to be received by the light receiving unit, and the prism is formed of a transparent or translucent hollow member, and the hollow member This is achieved by a two-liquid leak sensor in which a liquid or jelly-like substance is enclosed.

  The object of the present invention is to insert the light emitting part into the prism in order to shorten the distance from the light emitting part to the light receiving part, and to spread the light from the light emitting part and leak from the first optical fiber. In order to prevent the harmful effects of light, this is achieved more effectively by providing a shielding plate inside the prism.

  The present invention relates to a two-liquid leak sensor that detects oil that enters oil in a tank that stores water, a light emitter that is driven by a light emission drive unit to irradiate light vertically downward, is irradiated from the light emitter, and is provided in a holder. In order to reflect the light that has passed through the transmission hole and tilt it in the horizontal direction, a mirror disposed at an angle of 45 ° with respect to the horizontal direction, the incident surface on which the light tilted in the horizontal direction is incident, and the A prism having an exit surface from which light incident from the entrance surface exits, a reflecting mirror for reflecting the light exiting from the exit surface of the prism, and light reception for receiving the light reflected by the reflecting mirror And a light receiving processing unit for determining whether the liquid in which the prism is immersed is oil or water according to the presence or absence of light reception or the amount of light received by the light receiver, and the holder includes the mirror and the prism. And the reflector is The holder is attached to a float, and the float allows the prism to be immersed in the oil when oil enters the tank, and the holder is movable only in the vertical direction and fixed in the horizontal direction. In order to achieve this, the holder is passed through a guide rod, the prism is made of a transparent or translucent hollow member, and is achieved by a two-liquid leakage sensor in which water is sealed in the hollow member.

  The present invention relates to a two-liquid leak sensor that detects oil that enters oil in a tank that stores water, a light emitter that is driven by a light emission drive unit to irradiate light vertically downward, is irradiated from the light emitter, and is provided in a holder. A prism having an incident surface on which the light that has passed through the formed transmission hole is incident and an emission surface from which the light incident from the incident surface is emitted; and a reflecting mirror for reflecting the light emitted from the emission surface of the prism; A light receiver for receiving the light reflected by the reflecting mirror, and a light receiving process for determining whether the liquid in which the prism is immersed is oil or water according to the presence or absence or amount of light received by the light receiver The prism and the reflecting mirror are attached to the holder, the holder is attached to the float, and the float is in contact with the prism when oil enters the tank. The holder is passed through a guide bar so that the holder can be moved only in the vertical direction and fixed in the horizontal direction, and the prism is a transparent or translucent hollow member. This is achieved by a two-liquid leakage sensor in which water is enclosed in the hollow member.

  The object of the present invention is that when there is no liquid in the tank and the prism is in contact with air, the light emitted from the light emitter is transmitted to the light receiver as in the case where water is in the tank. In order to receive the light, the light emitter is a light emitting diode, and the corner cube array is not sealed in the case around the transmission hole, or the light emitter is a laser diode. Or the distance between the light emitter and the bottom of the tank is within 3 meters, the light emitter is a light emitting diode, or the reflector is a mirror made of stainless steel, etc. Or the reflector is a corner cube sealed in a transparent or translucent case, or the reflector is a corner By the is obtained by sealing a transparent or translucent case Yubuarei be more effectively achieved.

  Further, the object of the present invention is to provide the inclined surface by setting the inclination angle of the inclined surface of the prism to 27 ° or less, or so that the shape of the inclined surface side of the section of the prism becomes a plurality of right triangles. Each vertex of the plurality of isosceles triangles by dividing or by dividing the inclined surface so that the shape of the inclined surface side of the section of the prism becomes a plurality of isosceles triangles From the above, the light shielding plate is provided in the prism so as to bisect the isosceles triangle, and the light totally reflected by the inclined surface of the prism is shielded, or the light emitter or In order to prevent the harmful effects caused by the spread of the light emitted from the light emitting part, this is achieved more effectively by providing a shielding plate on a part of the inclined surface of the prism.

  The present invention relates to a two-liquid leakage sensor that detects liquid leakage by distinguishing between liquid types, and is a prism composed of a transparent or translucent hollow member, in which oil is sealed in the hollow member, and a cross section of the prism The shape is a quadrangle ABCD, and the quadrangle ABCD has ∠A of 70 ° to 75 ° and ∠B of 90 °, and the plane having the side AB of the prism as a cross section is the X plane and the side BC is the cross section. The surface is defined as the Y surface, and the surface having the side AD as a cross section is defined as the Z surface. A reflecting mirror, which is a mirror made of stainless steel or the like, is disposed on the Y surface, and irradiates light incident perpendicularly to the Z surface. A light emitting unit is provided, and light emitted from the light emitting unit is incident on the Z plane, and then enters either the X plane or the Y plane. The light incident on the X plane is totally reflected by the X plane. The transmitted or totally reflected light is reflected by the Y plane and the Z plane. The light is emitted in the normal direction and received by the light receiving unit, and the light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected or transmitted by the X plane. Then, the totally reflected light is emitted in the normal direction of the Z plane and is received by the light receiving unit, and the light emitting unit is irradiated from a light emitter driven by a light emission driving unit. The light guided by the first optical fiber is irradiated, and the light received by the light receiving unit is guided by the second optical fiber and received by the light receiver. The light is received depending on whether or not the light is received by the light receiver. The processing unit is achieved by a two-liquid leak sensor that determines whether the liquid in which the prism is immersed is oil or water.

  The present invention relates to a two-liquid leakage sensor that detects liquid leakage by distinguishing between liquid types, and is a prism composed of a transparent or translucent hollow member, in which oil is sealed in the hollow member, and a cross section of the prism The shape is a quadrangle ABCD, and the quadrangle ABCD has ∠A of 70 ° to 75 ° and ∠B of 90 °, and the plane having the side AB of the prism as a cross section is the X plane and the side BC is the cross section. The surface is defined as the Y surface, and the surface having the side AD as a cross section is defined as the Z surface. A reflecting mirror, which is a mirror made of stainless steel or the like, is disposed on the Y surface, and irradiates light incident perpendicularly to the Z surface. A light emitter driven by a light emission driving unit, and light emitted from the light emitter enters the Z plane, then enters either the X plane or the Y plane, and enters the X plane. Is totally reflected or transmitted by the X plane, and the totally reflected light is the Y plane. Reflected, emitted in the normal direction of the Z plane and received by a light receiver, the light incident on the Y plane is reflected by the Y plane, and the reflected light is reflected by the X plane. The light totally reflected or transmitted by the surface and totally reflected is emitted in the normal direction of the Z plane and is received by the light receiver. Whether or not the light is received by the light receiver Alternatively, the light reception processing unit is achieved by a two-liquid leakage sensor that determines whether the liquid in which the prism is immersed is oil or water according to the amount of received light.

  The present invention relates to a two-liquid leakage sensor that detects liquid leakage by distinguishing between the types of liquids, and is a prism formed of a transparent or translucent hollow member, in which oil is sealed in the hollow member, A Z-plane in which light is incident from the normal direction, an X-plane that is inclined by 70 ° to 75 ° with respect to the Z-plane, and a plurality of X-planes that are adjacent to the X-plane and are 90 on the X-plane. A Y-plane that is divided into a plurality of angles, and a reflecting mirror that is a mirror made of stainless steel or the like is disposed on the Y-plane, and irradiates light incident perpendicularly to the Z-plane of the prism. A light emitting unit is provided, and light emitted from the light emitting unit is incident on the Z plane, and then enters either the X plane or the Y plane. The light incident on the X plane is totally reflected by the X plane. The transmitted or totally reflected light is reflected by the Y plane and is in the normal direction of the Z plane. The light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected or transmitted by the X plane. The reflected light is emitted in the normal direction of the Z plane and received by the light receiving unit, and the light emitting unit is irradiated with a first light emitted from a light emitter driven by a light emission driving unit. The light guided by the fiber and received by the light receiving unit is guided by the second optical fiber and received by the light receiver. Depending on the presence or absence of light received by the light receiver or the amount of light received, the light receiving processing unit Is achieved by a two-liquid leak sensor that determines whether the liquid in which the prism is immersed is oil or water.

  The present invention relates to a two-liquid leakage sensor that detects liquid leakage by distinguishing between the types of liquids, and is a prism formed of a transparent or translucent hollow member, in which oil is sealed in the hollow member, A Z-plane in which light is incident from the normal direction, an X-plane that is inclined by 70 ° to 75 ° with respect to the Z-plane, and a plurality of X-planes that are adjacent to the X-plane and are 90 on the X-plane. A Y-plane divided into a plurality of angles, and a reflecting mirror, such as a stainless steel mirror, is disposed on the Y-plane, and irradiates light incident perpendicularly to the Z-plane of the prism. A light emitter driven by a light emission drive unit, and the light emitted from the light emitter enters the Z plane, then enters either the X plane or the Y plane, and enters the X plane. The light is totally reflected or transmitted by the X plane, and the totally reflected light is reflected by the Y plane. The light is emitted in the normal direction of the Z plane and is received by a light receiver. The light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected by the X plane. The light that is reflected or transmitted and totally reflected is emitted in the normal direction of the Z plane and is received by the light receiver, and whether or not the light is received by the light receiver or the amount of light received Thus, the light receiving processing unit is achieved by a two-liquid leakage sensor that determines whether the liquid immersed in the prism is oil or water.

  The present invention relates to a prism used in a two-liquid leakage sensor that detects liquid leakage by distinguishing between liquid types, and is composed of a transparent or translucent hollow member having an inclined surface, and the liquid or jelly enclosed in the hollow member A prism constituted by a substance, an inlet for injecting the liquid or the jelly-like substance, and a stopper of the inlet, and an air or vacuum gap between the stopper and the liquid or the jelly-like substance The inclined surface is divided so that the shape of the inclined surface side of the cross section of the prism becomes a plurality of right triangles. Or by dividing the inclined surface so that the shape of the inclined surface side of the cross section of the prism is a plurality of isosceles triangles, or the cross section of the prism A light shielding plate is provided inside the prism so as to bisect the isosceles triangle from each vertex of a plurality of isosceles triangles so as to shield the light totally reflected by the inclined surface of the prism. This is achieved by providing a shielding plate on a part of the inclined surface of the prism in order to prevent the harmful effects caused by the spread of light.

  The present invention relates to a prism used in a two-liquid leakage sensor that detects liquid leakage by distinguishing between liquid types, and relates to a transparent or translucent hollow member, a liquid sealed in the hollow member, and a liquid injection. A prism for a two-liquid leakage sensor, which is constituted by an inlet and a stopper of the inlet, and is provided with an air or vacuum gap between the stopper and the liquid, wherein the prism has a square cross-sectional shape The quadrangular ABCD is achieved by the fact that ７０A is 70 ° to 75 °, ∠B is 90 °, and a reflecting mirror is disposed on a surface having the side BC of the prism as a cross section. The

  The present invention relates to a prism used in a two-liquid leakage sensor that detects liquid leakage by distinguishing between liquid types, and relates to a transparent or translucent hollow member, a liquid sealed in the hollow member, and a liquid injection. A prism for a two-liquid leak sensor comprising an inlet and a stopper of the inlet, wherein an air or vacuum gap is provided between the stopper and the liquid. A Z-plane that is incident from a linear direction, an X-plane that is inclined by 70 ° to 75 ° with respect to the Z-plane, and an angle that is 90 ° to the X-plane adjacent to the X-plane. This is achieved by having a plurality of divided Y planes and a reflecting mirror disposed on the Y plane.

  According to the two-liquid leakage sensor according to the present invention, the leakage is detected based on the difference in the refractive index of light at the boundary surface between the prism and the liquid to be detected. The type of liquid such as water and oil and the presence or absence of liquid can be reliably distinguished and detected.

  In addition, the two-liquid leakage sensor according to the present invention can install an electric system at a position where there is no fear of contact with the liquid leakage by guiding light with an optical fiber or using a laser diode. Therefore, it is excellent in safety, has a simple structure, and can be manufactured at low cost.

  Furthermore, in the present invention, since a prism having a refractive index that is the same as or close to that of the liquid to be detected is used, light that travels substantially straight through the prism may be detected, and the configuration can be further simplified.

  In the two-liquid leakage sensor according to the present invention, light is emitted from a light emitter such as a light emitting diode to a prism having a predetermined refractive index, and the light irradiated to the prism is received by a light receiver. The presence / absence of liquid leakage and the type of liquid leakage are detected using the change in the refractive index of light depending on whether the liquid is immersed in the liquid leakage and the type of liquid leakage in which the prism is immersed. As a prism, a hollow transparent (or translucent) container in which a liquid or jelly-like transparent (or translucent) substance is enclosed is used, and a substance having the same or similar refractive index as the liquid to be detected is enclosed. A prism is used. In addition, the configuration of the present invention is simple, and by guiding light with an optical fiber or using a laser diode, the electrical system can be installed in a place where there is no risk of contact with liquid leakage. It is a liquid leakage sensor with no safety and excellent safety.

  First, the basic principle of the two-liquid leakage sensor according to the present invention will be described with reference to FIG.

  As shown in FIGS. 1A to 1C, the basic configuration of the two-liquid leakage sensor includes a light emitting unit 1 that emits directional light 2 and a vertical direction in which light 2 from the light emitting unit 1 is incident. A prism 3 having a refractive index n having a light incident surface 3A and a light exit surface 3B from which light is emitted; and two light receiving portions 4A arranged orthogonally to receive light emitted from the prism 3; It comprises a light receiving unit 4B. For example, when the prism 3 is immersed in a liquid 5 having substantially the same refractive index n as that of the prism 3, the light 2 substantially passes through the incident surface 3A and the exit surface 3B of the prism 3 as shown in FIG. The light travels straight, and the outgoing light 2A from the outgoing surface 3B is received by the light receiving portion 4A. On the other hand, when the prism 3 is immersed in a liquid 6 having a refractive index different from that of the prism 3, as shown in FIG. 1B, the light 2 is refracted by the exit surface 3B of the prism 3 and is emitted from the exit surface 3B. 2B is shifted from the light receiving unit 4A, and the amount of light received by the light receiving unit 4A is significantly reduced. When the prism 3 is not immersed in the liquid, the prism 3 is in contact with air, the light 2 is totally reflected by the emission surface 3B of the prism 3, and the total reflected light 2C is received by the light receiving unit 4B. When the prism 3 is in contact with air, the condition for the total reflection of the light 2 is given by the following equation (1).

ただし、θはプリズム３の出射面３Ｂの傾斜角であり、ｎはプリズム３の屈折
率である。
本発明に係る２液漏液センサでは、数１で与えられる条件を満たすプリズムを使用する。このようにして、受光部４Ａ及び受光部４Ｂでの受光の有無又は受光量を測定することによって、プリズム３を浸している液体の種類及び液体の有無を区別して検出することができる。

Here, θ is the inclination angle of the exit surface 3B of the prism 3, and n is the refractive index of the prism 3.
In the two-liquid leakage sensor according to the present invention, a prism that satisfies the condition given by Equation 1 is used. In this way, by measuring the presence or absence or amount of light received by the light receiving unit 4A and the light receiving unit 4B, it is possible to distinguish and detect the type of liquid in which the prism 3 is immersed and the presence or absence of the liquid.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 2 is a perspective view of the two-liquid leakage sensor 10 according to the present invention, which is an example of emitting and receiving light using an optical fiber. FIG. 3 is a block diagram. The light emitted from the light emitter 12 driven by the light emission drive unit 11 is guided through the optical fiber 13 and is applied to the prism 20 from the light emitting unit 13A at the tip thereof. The light emitted from the light emitting unit 13A is received by the light receiving unit 14A at the tip of the optical fiber 14 when the light travels substantially straight on the emission surface 20B of the prism 20, guided by the optical fiber 14, and photoelectrically received by the light receiver 15. An electrical signal corresponding to the received light amount is input to the detection processing unit 30 after being converted. In addition, when the light from the light emitting unit 13A is totally reflected by the emission surface 20B of the prism 20, it is received by the light receiving unit 16A at the tip of the optical fiber 16, guided by the optical fiber 16, and photoelectrically converted by the light receiver 17. An electrical signal corresponding to the amount of received light is input to the detection processing unit 30.

The prism 20 of the present embodiment includes a transparent or translucent hollow rectangular trapezoidal container 21, a liquid 24 having a refractive index n1 enclosed in the container 21, an injection member 22 for injecting the liquid 24, and a liquid 24. The prism 20 is housed in an outer case 26 and includes a plug 23 for preventing leakage. The light emitting portion 13A of the optical fiber and the light receiving portions 14A and 16A of the optical fibers 14 and 16 are fixed to the case 26.
In FIG. 2, the injection member 22 has a long column shape, but the length is arbitrary. The light emitting unit 13A is separated from the incident surface 20A of the prism 20, but may exist in the prism 20.
As shown in FIG. 4, a gap 27 for relaxing expansion and contraction of the liquid 24 due to temperature or the like is provided between the upper surface of the liquid 24 and the stopper 23 inside the container 21 of the prism 20. Yes. Thereby, it can respond to a temperature change. The gap 27 is filled with air or gas, or is vacuum.

  The detection processing unit 30 includes a light reception processing unit 31 and an alarm unit 32. The light reception processing unit 31 processes an electrical signal corresponding to the amount of light received from the light receivers 15 and 17, and the light reception units 15 and 17 The presence / absence of liquid leakage and the type of liquid leakage are determined according to the presence / absence of light reception and the amount of light received. The determination result in the light reception processing unit 31 is input to the alarm unit 32, and the alarm unit 32 is performed, for example, by emitting an alarm sound or by turning on or blinking the alarm lamps 32A to 32C. In the present embodiment, when the light 10A emitted from the light emitting unit 13A travels substantially straight on the emission surface 20B of the prism 20, it is received by the light receiving unit 14A, and the light 10A is totally reflected by the emission surface 20B of the prism 20. The light emitting unit 13A and the light receiving units 14A and 16A are disposed in the case 26 so that the light receiving unit 16A receives the light.

The state of the light path at the boundary between the prism 20 and the liquid 28 when the prism 20 is immersed in the liquid 28 having the same refractive index n1 as that of the liquid 24 will be described with reference to FIG. The light 10A traveling through the liquid 24 in the prism 20 is refracted into light 10B when entering the container 21 having a refractive index n2. When the light 10B enters the liquid 28 outside the prism 20 from the container 21, the light 10B is further refracted by the liquid 28 having a refractive index n1, and becomes the light 10C. The presence of the container 21 causes the path of the light 10 </ b> A to deviate straight, but the container 21 may be made thinner in order to reduce this deviation. Thus, by enclosing the liquid 24 having a refractive index that is the same as or close to the refractive index of the target liquid whose leakage is to be detected in the container 21, the refractive index of the entire prism 20 is the same as the refractive index of the leakage target liquid. Alternatively, light that travels substantially straight can be detected by approximation.
The substance to be enclosed in the container 21 of the prism 20 is not limited to a liquid, and a transparent or translucent jelly-like substance having a refractive index that is the same as or close to the refractive index of the liquid to be leaked may be enclosed.

  In the present embodiment, when the prism 20 satisfies the condition of the above formula 1 and there is no liquid leak 28 as shown in FIG. 5, the light 10A is received by the light receiving unit 16A and is not received by the light receiving unit 14A. In addition, as shown in FIG. 5, when there is a liquid leak 28 having a refractive index n1, the light 10A travels substantially straight, and the emitted light 10C is received by the light receiving unit 14A and not received by the light receiving unit 16A. Then, if there is a liquid leakage with a refractive index n3 different from the refractive index n1 of the liquid 24, the light emitted from the prism 20 becomes like 10C in FIG. 3, and the light is not received by the light receiving unit 14A or the amount of light received is remarkably large. Decrease. Also in this case, the light receiving unit 16A does not receive the light. Accordingly, the light reception processing unit 31 detects the presence / absence of light received by the light reception unit 16A (light receiver 17) and the light reception unit 14A (light receiver 15) and the amount of light received, thereby determining the presence / absence of the liquid immersing the prism 20 and the liquid. It is possible to detect by distinguishing the type. According to the processing result of the light receiving processing unit 31, the alarm unit 32 turns on the LED 32A when there is no leakage, and turns on the LED 32B when there is leakage and the liquid (for example, oil) having the same refractive index n1 as the liquid 24. The LED 32C is turned on or blinked for a liquid (for example, water) having a refractive index n3 different from the liquid 24 due to liquid leakage.

In the above embodiment, two light leaks are detected by the two light receivers 14A (light receiver 15) and the light receiver 16A (light receiver 17). However, as shown in FIG. It can also be set as the structure which provided the container 19. FIG. For example, when the prism 20 is immersed in oil, that is, when oil leaks, the light 10B emitted from the emission surface 20B travels substantially straight and is received by the light receiving unit 14A. If the inclination angle of the exit surface 20B of the prism 20 is 45 °, the light 10A emitted from the light emitting portion 13A enters the exit surface 20B at an incident angle of 45 °, and the refraction angle of the light 10B becomes θ _A = 45 °. . On the other hand, when water leaks, the refraction angle θ _B of the light 10C emitted from the emission surface 20B is 1.5 according to Snell's law, assuming that the refractive index of oil is 1.5 and the refractive index of water is 1.33. The following equation 2 holds.

数２より、θ_Ｂ＝５２．８９°で、θ_B−θ_A＝７．８９°となる。従って、光１０Ｃは、光１０Ｂから略８°だけ傾いた方向に進む。この方向に受光部１８Ａを配設すると、プリズム２０が水に浸かっている場合の出射光１０Ｃが、受光部１８Ａで受光され、光ファイバ１８を誘導されて受光器１９で検出される。また、プリズム２０の屈折率がｎ＝１．５で、傾斜角がθ＝４５°であることから、前記数１の条件を満たすので、漏液が無くプリズム２０が空気と接触している場合、光１０Ａはプリズム２０の出射面２０Ｂで全反射する。このような構成とすることにより、受光部１４Ａ、１８Ａ及び１６Ａのいずれかで受光された光は、それぞれ光ファイバ１４、１８及び１６で誘導されて、受光器１５、１９及び１７で受光される。受光処理部３１で受光器１５、１９及び１７のいずれかで受光したかによって、油の漏液、水の漏液を区別すると共に、漏液が無いことを確実に判定でき、その判定結果に応じて警報部３２から警報を発する。

From Equation 2, θ _B = 52.89 ° and θ _B −θ _A = 7.89 °. Accordingly, the light 10C travels in a direction inclined by approximately 8 ° from the light 10B. When the light receiving portion 18A is disposed in this direction, the emitted light 10C when the prism 20 is immersed in water is received by the light receiving portion 18A, guided through the optical fiber 18, and detected by the light receiver 19. Further, since the refractive index of the prism 20 is n = 1.5 and the inclination angle is θ = 45 °, the condition of the above equation 1 is satisfied, and therefore there is no leakage and the prism 20 is in contact with air. The light 10A is totally reflected by the exit surface 20B of the prism 20. With this configuration, the light received by any of the light receiving portions 14A, 18A, and 16A is guided by the optical fibers 14, 18, and 16 and received by the light receivers 15, 19, and 17, respectively. . Depending on whether the light receiver 15, 19, or 17 receives light in the light receiving processing unit 31, it is possible to discriminate between oil leakage and water leakage and reliably determine that there is no leakage. In response, an alarm is issued from the alarm unit 32.

  The light emitting unit 13A and the light receiving unit 16A may exist in the prism 20.

  By the way, in order to detect water invading into a tank storing oil such as gasoline or petroleum, the specific gravity of water is larger than that of oil, and therefore it is necessary to dispose a prism at the bottom of the tank. In FIG. 7, in order to arrange the case 41 with the prism 20 on the bottom of the tank 40, a lid member 42 is disposed on the tank 40, and a cylinder 43 in which the lid member 42 and the case 41 are coupled is used. It is a block diagram of the 2 liquid leak sensor (3rd Embodiment) in a case. Oil 44 is stored in the tank 40, and a liquid 24 having a refractive index that is the same as or similar to that of the oil 44 is injected into the prism 20, and the light emitting unit 45 </ b> A passes through the optical fiber 45 into the case 41. In addition to being attached, a light receiving portion 46A of the optical fiber 46 is attached. Moreover, in this embodiment, since it is sufficient to detect only water leakage (intrusion), the light receiving unit is installed only in one place.

  In such a configuration, the light 47 guided by the optical fiber 45 is irradiated onto the prism 20 from the light emitting portion 45A and is emitted from the emission surface 20B. When water does not enter the oil 44 stored in the tank 40, the light 47 travels substantially straight and is received by the light receiving unit 46A. When water enters the oil 44 stored in the tank 40, the incident light 47 is refracted by the exit surface 20B of the prism 20, so that the light 47 is not received by the light receiving portion 46A or the amount of received light is significantly reduced. . Therefore, water that has entered the tank 40 can be detected.

  In addition, when it is necessary to detect not only whether or not water has entered the oil 44 in the tank 40 but also the presence or absence of the oil 44 in the tank 40, the light receiving unit 2 is installed as shown in FIG. It is necessary to install in the place. Further, in FIG. 7, the case 41 is pressed by the lid member 42 and the cylinder 43 in order to arrange the prism 20 and the case 41 at the bottom of the tank 40, but the case 41 and the cylinder 43 are not used without using the lid member 42. The prism 20 and the case 41 may be sunk by either increasing the weight or attaching a weight. In FIG. 7, the prism 20 and the case 41 are disposed on the center bottom surface of the tank 40. Further, the light emitting unit 45A may exist in the prism 20.

  On the other hand, in order to detect the oil that enters the tank storing water, the specific gravity of the oil is lighter than that of the water, and therefore it is necessary to float the prism on the water surface. FIG. 8 shows a liquid leakage detection part of the two-liquid leakage sensor (fourth embodiment) for this purpose. In order to float the prism 20 on the water surface, a holder 51 is installed on the inner surface of the donut-shaped float 50, The prism 20 is mounted on the holder 51. In addition, two holding plates 52 and 53 are suspended from both ends of the holder 51, that is, at a position sandwiching the prism 20, and the light emitting portion 54 </ b> A of the optical fiber 54 is fixed to the holding plate 52. The light receiving portion 55 </ b> A of the optical fiber 55 is fixed to 53.

  In order to be able to detect oil with the two-liquid leakage sensor of this embodiment, it is necessary to select a float so that the prism 20 is immersed in the oil when the oil enters the tank.

  In such a configuration, the liquid leakage detection unit shown in FIG. 8 floats in water or water in the tank, and the light 56 guided by the optical fiber 54 is applied to the prism 20 from the light emitting unit 54A. When 20 is immersed in water in the tank, the light 56 is refracted by the emission surface 20B of the prism 20, and is not received by the light receiving unit 55A, or the amount of received light is significantly reduced. Thereby, it can be detected that the leak detection unit floats in water or in water. When oil enters the tank and an oil film or layer is formed on the water, the prism 20 is immersed in the oil, so that the light 56 travels substantially straight and is received by the light receiving portion 55A. Thus, it is determined whether or not the prism 20 is immersed in oil based on the presence or absence of light reception and the amount of light received, and an alarm is issued according to the determination result.

  When it is necessary to detect the presence or absence of water in the tank simultaneously with the intrusion of oil into the tank, or when it is necessary to detect the presence or absence of liquid in the tank, it is shown in FIG. 3 or FIG. Thus, it is necessary to arrange a plurality of light receiving parts.

  Further, in the present invention, by using the reflecting mirror 60 as shown in FIG. 9, both the light emitting part 61A and the light receiving part 62A can be arranged on the incident surface 20A side of the prism 20. That is, the liquid leakage detection unit of the two-liquid leakage sensor is disposed in the liquid 64 stored in the tank 63, and the light emitting unit 61A of the optical fiber 61 that guides the light from the light emitter and the light receiver. The light receiving part 62A of the optical fiber 62 for guiding light is attached in close proximity to the parallel part of the L-shaped holder 65, and the prism 20 is disposed in the vertical part of the holder 65. A reflecting mirror 60 is attached to the lower end portion of the holder 65 in order to reflect the light 66A emitted from the emission surface 20B of the prism 20 toward the light receiving portion 62A. When a mirror plate made of stainless steel or aluminum is used for the reflecting mirror 60 or when the distance from the prism 20 to the reflecting mirror 60 is large, the corner cube or the corner cube array (reflex reflector) should not be in contact with the liquid. Use in a transparent container. The holder 65 is supported by a support rod 67 that moves up and down, and the liquid leakage detection unit can be installed at an arbitrary position by the vertical movement of the support rod 67.

  In such a configuration, when the liquid 64 in which the prism 20 is immersed and the liquid injected into the prism 20 are both oil, the light 66A guided by the optical fiber 61 and emitted from the light emitting unit 61A is converted into the prism 20. The incident surface 20 </ b> A and the exit surface 20 </ b> B travel substantially straight and are reflected by the lower reflecting mirror 60. The reflected light 66B reflected by the reflecting mirror 60 travels substantially straight on the exit surface 20B and the entrance surface 20A of the prism 20, and is received by the light receiving unit 62A disposed so as to be close to the light emitting unit 61A.

  When the liquid 64 in which the prism 20 is immersed is water, the refractive index of water is different from the refractive index of the prism 20, so that the light 66A emitted from the light emitting unit 61A is refracted by the emission surface 20B of the prism 20, Since the refracted light is reflected by being inclined by the reflecting mirror 60, the light is not received by the light receiving unit 62A. As described above, when the reflecting mirror 60 is a specular plate, the reflected light faces different directions and is not received by the light receiving unit 62A. However, when the reflecting mirror 60 is a corner cube or a corner cube array, the light is not received. Since the light is reflected in the incident direction, the reflected light 66B is received by the light receiving unit 62A. Therefore, when the reflecting mirror 60 is a corner cube or a corner cube array, it is necessary to sufficiently increase the distance from the prism 20 to the reflecting mirror 60 so that the light refracted by the prism 20 does not reach the reflecting mirror 60.

In this manner, it is possible to distinguish and detect whether the liquid in which the prism 20 is immersed is oil or water according to the amount of light received by the light receiving unit 62A.
In the present embodiment using the reflecting mirror 60, the third embodiment shown in FIG. 7 for detecting the water entering the tank in which the oil is stored and the oil entering the tank in which the water is stored are used. Can be applied to the fourth embodiment shown in FIG. Further, the liquid to be detected is not limited to oil and water, and the presence or absence of an arbitrary liquid can be detected by enclosing a liquid or jelly-like substance having the same refractive index as the liquid to be detected in the prism 20. Can be. Further, the light emitting unit 61A and the light receiving unit 62A may be included in the prism 20.

  In any of the first to fifth embodiments described above, in order to install the electrical system at a position where it does not contact the liquid, the light for emitting and receiving light is guided by the optical fiber. However, as shown in FIG. It is also possible to adopt a direct light emitting / receiving type configuration using a laser diode as a light emitter without using a light source.

  In the present embodiment, water 71 is stored in the tank 70, and the leak detector 80 of the two-liquid leak sensor for detecting oil such as gasoline entering the water 71 includes a donut-shaped float 81. A hole 82A is formed in the holder 82 installed between the upper inner wall surfaces of the float 81, and the guide rod 72 is engaged with the hole 82A, so that the liquid leakage detector 80 can be freely moved along the guide rod 72. While moving up and down, it floats on the water 71. The leak detector 80 can only be moved in the vertical direction by the guide rod 72, and does not move in the horizontal direction. The holder 82 is provided with a transmission hole 82B for transmitting light, the prism 20 is disposed on the lower surface side of the holder 82, and a transparent or translucent material is provided on both sides of the prism 20 on the lower surface side of the holder 82. A rectangular parallelepiped case 83 and 84 are disposed, a corner cube array reflecting mirror 85 is installed on the inner surface side of the case 83, and a mirror 86 inclined at 45 ° is installed in the case 84.

  Further, an L-shaped column 74 is installed on the ground 73 outside the tank 70, and a drive controller 90 for a two-liquid leakage sensor is provided at the tip of the column 74. The drive control unit 90 includes an L-shaped base 91, a detection processing unit 92 is provided on the base 91, and a light receiver 93 is attached to a vertical portion of the base 91. A light emitter 96 is attached to the center of the back surface of the light source, and a support member 94 made of an L-shaped transparent material or translucent material is attached to the support member 94. A half mirror 95 inclined at 45 ° is installed on the support member 94. Has been. A guide bar 72 is installed between the base 91 and the bottom surface of the tank 70.

  The light emitter 96 corresponds to the position of the transmission hole 82B of the holder 82, and the prism 20 is filled with water. The light emitter 96 is driven by the detection processing unit 92, and the light amount signal received by the light receiver 93 is input to the detection processing unit 92 and processed.

  In such a configuration, the light 96A irradiated vertically downward from the light emitter 96 first enters the half mirror 95 disposed at an angle of 45 ° with respect to the horizontal direction, and half of the light 96A is transmitted. , Half is reflected. The light 96B that has passed through the half mirror 95 passes through the transmission hole 82B of the holder 82, is bent 90 ° by a mirror 86 that is disposed at an angle of 45 ° with respect to the horizontal direction, and is reflected in the horizontal direction. The light 96C reflected by the mirror 86 enters from the entrance surface 20A of the prism 20 and exits from the exit surface 20B.

  When both the entrance surface 20A and the exit surface 20B of the prism 20 are immersed in water, the light 96C travels substantially straight through the prism 20, enters the reflecting mirror 85, and the reflected light 96D is reflected. The reflected light 96D travels in the opposite direction along the path along which the incident light has traveled, is reflected by the mirror 86, and enters the half mirror 95. Half of the reflected light 96 </ b> D that has entered the half mirror 95 passes through and travels straight, and half is reflected and received by the light receiver 93.

  When oil enters the tank 70 and an oil film or layer is formed on the surface of the water 71 and the incident surface 20A and the exit surface 20B of the prism 20 are immersed in the oil, the light 96C is incident on the incident surface 20B of the prism 20. Therefore, the reflection mirror 85 is not reached. As a result, the amount of light received by the light receiver 93 is significantly reduced or becomes 0, and oil intrusion (leakage) can be detected.

  The specific gravity of the liquid leakage detection unit 80 in this example is smaller than that of water and larger than that of oil, and the liquid leakage detection unit 80 floats with respect to the water 71 in the tank 70, and the incident surface 20 </ b> A and the emission surface of the prism 20. The surface 20 </ b> B is immersed in the water 71. For this reason, when the oil enters, the leakage detector 80 sinks in the oil, and the incident surface 20A and the emission surface 20B of the prism 20 are immersed in the oil. Further, in FIG. 10, the drive control unit 90 is attached to the support column 74, but it is also possible to attach it to another fixing member instead of the support column.

  In the sixth embodiment shown in FIG. 10, a laser diode is used as the light emitter 96 so that the light beam can reach far. However, when the depth of the tank 70 is 3 meters or less and shallow, the light emitter 96 emits light. A diode may be used.

  FIG. 11 shows another embodiment (seventh embodiment) of a direct light emitting / receiving type, and in this embodiment, a half mirror and a direction changing mirror are not used.

  That is, also in the present embodiment, the water 101 is stored in the tank 100, and the leak detection unit 110 of the two-liquid leak sensor for detecting the oil entering the water 101 includes the donut-shaped float 111. The holder 112 installed between the inner wall surfaces of the upper part of the float 111 is provided with a hole 112A, and the guide rod 102 is engaged with the hole 112A. The liquid leakage detection unit 110 is freely movable along the guide rod 102. And floats in the water 101. The holder 112 is provided with a transmission hole 112B for transmitting light. An L-shaped support member 113 is attached to the lower surface of the holder 112, and the prism 20 is installed on the support member 113 with the inclined surface 20A facing upward. Yes. A corner cube array reflecting mirror 114 is installed on the bottom surface of the support member 113.

  In addition, a drive control unit 120 for a two-liquid leakage sensor is provided above the tank 100, a detection processing unit 122 is provided on the base 121, and a light emitter 123 and a bottom surface of the base 121 are provided. A light receiver 124 is provided in close proximity. A guide rod 102 is installed between the base 121 and the bottom surface of the tank 100. It is assumed that water is enclosed in the prism 20 of this example.

  In this embodiment, in order to detect the liquid near the liquid surface, the incident surface 20A of the prism 20 is an inclined surface, and water is enclosed in the prism 20, so that oil enters the tank 100. If not, the light 123 </ b> A emitted from the light emitter 123 passes through the transmission hole 112 </ b> B of the holder 112, travels substantially straight on the incident surface 20 </ b> A and the exit surface 20 </ b> B of the prism 20, and is reflected by the reflecting mirror 114. The reflecting mirror 114 is attached to a support member 113 sealed in a transparent or translucent case so that the corner cube array does not come into contact with the liquid, and the incident light 123A travels as the light 123B reflected by the reflecting mirror 114. The light travels in the reverse direction and is received by the light receiver 124.

  When oil enters the tank 100 and an oil film or layer is formed on the liquid surface, the incident surface 20A and the exit surface 20B of the prism 20 are immersed in the oil, and the incident light 123A is incident on the incident surface of the prism 20. Refracted. For this reason, the reflected light 123B does not reach the light receiver 124, and the light is not received or the amount of received light is significantly reduced.

In this manner, whether or not oil has entered the tank 100 can be detected by detecting the presence or absence or amount of light received by the light receiver 124. In the present embodiment, the light 123A irradiated vertically downward from the light emitter 123 is directly incident on the incident surface of the prism 20, and the type of liquid and the presence or absence of the liquid are distinguished and detected. In the embodiment shown in FIG. 10 and FIG. 11, when there is no water in the tank and the prism 20 comes into contact with air, the prism 20 is bent. Since the rate is greater than air, the light 130 travels relative to the prism 20 as shown in FIG. At this time, if the light 130 deviates from the reflecting mirror 131 of the corner cube array, the light 130 is not reflected by the reflecting mirror 131 and is not received by the light receiver. The detection result in this case is the same as when the prism 20 is immersed in oil, and the purpose is to detect the oil that originally enters the tank, but the case where the oil has entered and the tank It becomes impossible to distinguish from the case where the water is running out.

  In order to avoid this, the leakage detection unit 110A of the two-liquid leakage sensor is configured to detect the state in which water is lost in the tank without distinguishing from the case where only water is stored in the tank. An example of the configuration will be described with reference to FIG. In the embodiment of FIG. 13 (eighth embodiment), a light emitting diode is used as the light emitter 123 so that the light emitted from the light emitter 123 has a certain extent. Around the transmission hole 112B provided in the holder 112 for transmitting light, a corner cube array reflecting mirror 115 for concentrically reflecting the light 123C from the light emitting diode 123 is provided in a donut shape. .

  When there is no water in the tank, the light 130C transmitted through the transmission hole 112B is refracted when entering the prism 20, and is not reflected by the reflecting mirror 114. However, since the reflecting mirror 115 is concentrically arranged around the transmission hole 112B and the light 123C emitted from the light emitting diode 123 has a certain extent, a part of the irradiated light is reflected. The light is reflected by the mirror 115 and received by the light receiver 124 disposed close to the light emitter 123.

  When oil enters the tank, since the liquid sealed in the prism 20 is water, the light incident on the prism 20 from the light emitter 123 is refracted or totally reflected, and is reflected by the reflecting mirror 114. First, the light receiver 124 does not receive the light. In addition, since the leakage detection unit 110A is submerged in oil, the reflecting mirror 115 disposed on the holder 112 is immersed in the oil and loses its function as a reflecting mirror. The held light 123 </ b> C is not reflected by the reflecting mirror 115 and is not received by the light receiver 124.

  When water is stored in the tank and no oil enters, the light emitted from the light emitter 123 is reflected by the reflecting mirrors 114 and 115 and received by the light receiver 124.

  In this way, by detecting the presence / absence of light received by the light receiver 124 and the amount of light received, the case where there is no water in the tank can be detected as the case where only water is stored in the tank, and oil is contained in the tank. It can be distinguished from the case of intrusion, and the purpose of detecting oil intrusion (leakage) into the tank can be achieved.

  The above-described third to eighth embodiments are two-liquid leakage sensors for distinguishing and detecting water and oil, and when the liquid that immerses the prism is either water or oil, the light travels almost straight. In the other case, the light is refracted or totally reflected by the inclined surface of the prism. In order to clearly distinguish the presence or absence of light reception by the light receiver, it is better to totally reflect light than to refract light on the inclined surface of the prism.

FIG. 14 shows the path of light incident on the boundary surface between oil and water, and light LG incident from oil to water at an incident angle θ _G travels in water as light LH at a refraction angle θ _H. . At this time, the following relationship 3 holds.

ただし、ｎ_ＧＨは油に対する水の相対屈折率であり、ｎ_Ｇは油の屈折率、ｎ_Ｈは水の
屈折率である。
数３より、下記数４が導かれる。

However, n _GH is the relative refractive index of water to oil, n _G is the refractive index of the oil, n _H is the refractive index of water.
From Equation 3, the following Equation 4 is derived.

従って、全反射の条件は下記数５によって与えられる。

Therefore, the condition of total reflection is given by the following equation (5).

ｎ_Ｇ＝１．５、ｎ_Ｈ＝１．３３とすると、全反射するためには、屈折角θ_Ｇは下記数６の条件を満たす必要がある。

Assuming that n _G = 1.5 and n _H = 1.33, the refraction angle θ _G must satisfy the condition of the following formula 6 in order to totally reflect.

従って、

Therefore,

であれば全反射する。

If so, it is totally reflected.

  FIG. 15 is a diagram for explaining the relationship between the inclination angle θ of the emission surface 20B and the incidence angle of the emission surface 20B of the light L1 incident on the emission surface 20B of the prism 20 with the inclination angle θ. It can be seen that the angle of incidence on the surface 20B is “90 ° −θ”. When the liquid 24 sealed in the prism 20 is oil and the liquid L2 that immerses the prism 20 is water, the light L1 is totally reflected by the exit surface 20B.

が成立する。即ち、出射面２０Ｂの傾斜角は

Is established. That is, the inclination angle of the exit surface 20B is

であれば良い。

If it is good.

  Equation 9 which is a condition for total reflection of light incident on the inclined surface of the prism 20 is an inclination angle when the liquid 24 sealed in the prism 20 is water and the liquid soaking the prism 20 is oil. This is true even when the light L1 is incident on the incident surface 20A of the prism 20 having θ. Therefore, in the third to eighth embodiments, the liquid 24 sealed in the prism 20 and the liquid L2 in which the prism is immersed are different by making the inclination angle of the inclined surface of the prism 20 satisfy the condition of Equation 9. In this case, the light incident on the inclined surface 20B can be totally reflected. That is, by making the prism 20 satisfy the condition of Equation 9, it is possible to clearly distinguish the presence or absence of light reception by the light receiver, and to reduce the possibility of erroneous detection.

  As described above, when satisfying Equation 9 which is a condition for total reflection, when the inclined surface is formed as one surface, the distance between the light incident surface and the light exit surface of the prism increases, Depth increases. For this reason, as shown in FIG. 16, by dividing the inclined surface 20D of the prism 20 and providing a plurality of small triangles, the depth of the entire prism can be reduced. FIG. 16 is a cross-sectional view of the prism 20 when the inclined surface 20D is divided into a plurality of right-angled triangular inclined surfaces so that light is refracted or totally reflected in the same direction on any exit surface 20B. The inclination angle θ of the inclined surface 20D satisfies the condition of Formula 9, and one of the flat surface 20C and the inclined surface 20D is a light incident surface, and the other surface is a light emitting surface.

  FIG. 17A is a cross-sectional view of the prism 20 in the case where the inclined surface 20D is divided into a plurality of isosceles triangles. Light that is refracted or totally reflected from the exit surface 20B is opposite in the adjacent surface. Come to face. As shown in FIG. 17A, the size of the apex angle of the isosceles triangle is 2θ, and θ satisfies the condition of Equation 9. When the light incident from the flat surface 20C is totally reflected by the inclined surface 20D, it enters the adjacent inclined surface, which may cause a harmful effect of leakage detection. In order to prevent this, as shown in FIG. 17B, a shielding plate 20E for blocking light may be provided between adjacent inclined surfaces.

  On the other hand, since the light irradiated from the optical fiber has a weak directivity and has a certain extent, the spread may cause a harmful effect. For example, as shown in FIG. 18, it is assumed that the light L3 that travels straight from the light emitting portion 140A of the optical fiber 140 and enters the incident surface 20A is totally reflected by the exit surface 20B of the prism 20. Since the light L3 emitted from the light emitting portion 140A of the optical fiber 140 has a spread, there is light incident obliquely on the exit surface 20B of the prism 20 like the light L4, and this light L4 is totally reflected by the exit surface 20B. The light may be refracted and reach the light receiving part 141A of the optical fiber 141. For this reason, there is a possibility that the two-liquid leakage sensor may notify a false alarm to the outside.

  In order to prevent this adverse effect, shielding plates 20E1 to 20E3 may be provided on the prism 20 as shown in FIG. In the embodiment of FIG. 19A, in order to prevent the light that has spread with respect to the straight light L5 from passing through the emission surface 20B of the prism 20 and reaching the light receiving portion 141A, the emission surface of the prism 20 is used. A shielding plate 20E1 is layered on a part of 20B. Since the light energy can be reduced by bringing the light emitting portion 140A and the light receiving portion 141A closer to each other, in the embodiment of FIG. 19B, the tip of the optical fiber 140 is moved from the incident surface 20A of the prism 20 to the inside of the prism 20. In addition, the light-emitting portion 140A is provided inside the prism 20, and the shielding plate 20E2 is provided along the optical path inside the prism 20 in order to prevent the adverse effect of the spread of light from the optical fiber 140. In the embodiment of FIG. 19C, the tip of the optical fiber 140 is provided inside the prism 20 in order to bring the light emitting part 140A closer to the light receiving part 141A, and the light leaking from the optical fiber 140 and the light emitting part 140A. A shielding plate 20E3 is provided around the optical fiber 140 in order to prevent harmful effects caused by the spread of light from the optical fiber 140.

  Further, by attaching a reflecting mirror to one surface of the prism, the prism can have both roles of the prism and the reflecting mirror. FIG. 20 shows such an example, in which a reflecting mirror 150 is attached to one surface of a prism having a square ABCD. The prism 20 is configured such that the liquid 152 can be injected into a transparent or translucent hollow container 151 having a quadrangular ABCD cross section. The liquid 152 is injected from the injection port 153 and enclosed in the container 151 by a stopper 154. Has been. An air or vacuum gap 155 is provided between the liquid 152 and the stopper 154 in order to reduce expansion and contraction of the liquid 152. The substance to be injected into the container 151 is not limited to a liquid, and may be a transparent or translucent jelly-like substance.

  FIG. 21 is a cross-sectional view of the prism 20 of FIG. 20 taken along the line XX. In the quadrangular ABCD having a cross-sectional shape, ∠A is 70 ° to 75 ° and ∠B is perpendicular. Here, the encapsulated liquid 152 is oil, and the reflecting mirror 150 is attached to the Y surface whose cross section is the side BC. The reflecting mirror 150 is a stainless steel end plate.

  When the light L10 is perpendicularly incident on the Z plane whose cross section is the side AD, the incident light L10 is incident on the X plane whose cross section is the side AB at an incident angle of 70 ° to 75 °. When the liquid 156 in which the prism 20 is immersed is water, the light L10 incident on the X plane satisfies the condition of the equation 7, so that the light L10 is totally reflected to become the light L11, and the reflecting mirror 150 is adhered to the Y. Incident on the surface. The light L12 reflected by the reflecting mirror 150 is emitted from the Z plane in a direction perpendicular to the Z plane. That is, the light L12 is emitted in the direction opposite to the light L10. On the other hand, when the liquid 156 is oil, the light L10 travels substantially straight and no reflected light is generated.

  Although the case where the light L10 is incident on the X plane and then reflected on the Y plane has been described, the incident light may be reflected on the Y plane and then incident on the X plane. For this reason, a light emitting unit is disposed so that light is incident perpendicular to the Z plane and light is incident on either the X plane or the Y plane, and the light emitted perpendicular to the Z plane is received. By disposing the light receiving portion in this manner, water and oil can be distinguished and detected.

  In the ninth embodiment shown in FIG. 22, a holder 160 to which a prism 20 having a square cross section as described in FIGS. 20 and 21 is attached is attached to the float 161, and the light L20 is applied to the X and Y surfaces of the prism 20. And a light emitter 162 that irradiates L21 and a light receiver 163 that receives light L20A and L21A from the Y plane and the X plane are disposed close to each other. As described above, when the light emitter 162 and the light receiver 163 are disposed far from the prism 20, the light emitted from the light emitter 162 is, as shown, light L20 incident on the X plane and light L21 incident on the Y plane. There is. When the liquid sealed in the prism 20 is oil and the liquid 164 immersed in the prism 20 is water, both the light L20 and the light L21 are totally reflected on the X plane and received by the light receiver 163.

  In the tenth embodiment shown in FIG. 23, the light from the light emitter is guided by the optical fiber 170, and the light received by the light receiving unit 171A is guided to the light receiver by the optical fiber 171. The light receiving portion 171A is attached to a holder 172 having an L-shaped cross section so as to be disposed on the same side of the prism 20 having a square cross section. The prism 20 is attached to the vertical part of the holder 172 so that the light L30 from the light emitting part 170A is incident on the X plane and the light L31 reflected by the Y plane is received by the light receiving part 171A. As described above, by arranging the light emitting unit 170A and the light receiving unit 171A on the same side as the prism 20, it is not necessary to bend the optical fibers 170 and 171 forcibly, and it is possible to prevent the optical fiber from being burdened. .

  As described above, the prism having a square section to which the reflecting mirror is attached can be applied to the embodiment in which the prism and the reflecting mirror shown in FIGS. 9 to 11 and 13 are individually arranged. The light emitting unit 170A and the light receiving unit 171A are separated from the prism surface in the figure, but may exist in the prism 20.

  As shown in FIG. 24, by dividing the X-plane and Y-plane of the prism 20 into a plurality, the height H of the prism 20 can be reduced even if the Z-plane on which light is first incident is widened. .

  As shown in FIG. 25, when light is emitted vertically downward from a light emitting portion 180A of an optical fiber 180 to a prism having a square section, the light emitted from the light emitting portion 180 has a spread. When the liquid sealed in the prism 20 is oil and the liquid immersed in the prism 20 is water, the light L40A irradiated vertically downward from the light emitting unit 180A and the light L40B spread from the vertical direction are relative to the X plane. Since the incident angle satisfies the condition of Equation 7, total reflection is performed on the X plane. On the other hand, the light L40C spread from the vertical direction has an incident angle with respect to the X plane smaller than that of the light L40A, and the light is transmitted depending on the size of the spread.

  In order to prevent such harmful effects due to the spread of light, as shown in FIG. 26, the X plane is set so that the light spread from the light emitting portion 180A always satisfies the condition of Equation 7 and is totally reflected by the X plane. It may be curved. By doing so, the light L50A emitted vertically downward from the light emitting unit 180A, the light L50B spread from the vertical direction, and the light L50C are both totally reflected on the X plane.

  In the ninth and tenth embodiments, when the prism 20 is immersed in water, the liquid sealed in the prism 20 is made oil so that the light is totally reflected on the X surface of the prism 20. The prism may be made of a transparent material having a refractive index that is similar to or larger than that of oil such as acrylic, nylon, glass, or the like without enclosing the liquid.

  As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to this, In the range which does not deviate from the meaning, it can change suitably. In particular, in each of the above embodiments, the prism is configured by a container and liquid is sealed in the container. However, the prism is not configured by the container and the liquid in the container, but the material of the prism itself is detected for leakage. You may make it comprise as what has the refractive index relevant to a liquid. In each embodiment, the oil is simply described as oil, but the oil is gasoline (refractive index = 1.442), light oil (refractive index = 1.352), machine oil (refractive index = 1.480), benzene (refractive). Rate = 1.501).

It is a figure for demonstrating the basic principle of the 2 liquid leak sensor which concerns on this invention. It is a perspective view which shows the 2 liquid leak sensor (1st Embodiment) which concerns on this invention. It is a block block diagram of the 2 liquid leak sensor (1st Embodiment) which concerns on this invention. It is a perspective view which shows an example of the prism which concerns on this invention. It is a figure for demonstrating the principle of the prism in this invention. It is a block block diagram of the 2 liquid leak sensor (2nd Embodiment) which concerns on this invention. It is sectional drawing which shows the structural example of the 2 liquid leak sensor (3rd Embodiment) for detecting the water which penetrate | invades in the tank which stored oil. It is a perspective view which shows the structural example of the liquid leak detection part of the 2 liquid leak sensor (4th Embodiment) for detecting the oil which penetrate | invades in the tank which stored water. It is sectional drawing which shows the structural example of the 2 liquid leak sensor (5th Embodiment) of this invention which uses a reflective mirror. It is a partial cross section perspective view which shows an example of the 2 liquid leak sensor (6th Embodiment) of the form which irradiates light to a prism directly from a light-emitting device. It is a partial cross section perspective view which shows another embodiment (7th Embodiment) of the 2 liquid leak sensor of the form which irradiates light to a prism directly from a light-emitting device. It is a figure which shows the example of the course of the light in the air of a prism. It is a perspective view which shows the structural example of the liquid leak detection part of the 2 liquid leak sensor (8th Embodiment) which installed the reflective mirror around the permeation | transmission hole. It is a figure for demonstrating the course of the light which injects into water from oil. It is a figure explaining the relationship between the incident angle of the light which injects into the output surface of inclination angle (theta) of a prism, and inclination angle (theta). It is sectional drawing which shows the example of the prism which made the cross section of the inclined surface of a prism divide | segment into the hypotenuse of a several right triangle. It is sectional drawing which shows the example of the prism which made the cross section of the inclined surface of a prism become a several isosceles triangle. It is a figure for demonstrating the path | route of the light which went straight from the light emission part, and the light which spread from the light emission part. It is a figure which shows the example of the prism which provided the shielding board in order to prevent the bad effect of the spreading of the light from a light emission part. It is a perspective view which shows the example of the prism which stuck the reflecting mirror on one surface of the prism whose cross-sectional shape is a rectangle. It is sectional drawing which shows the example of the prism which stuck the reflecting mirror on one surface of the prism whose cross-sectional shape is a square. It is a schematic diagram which shows the 2 liquid leak sensor (9th Embodiment) which has arrange | positioned the light emitter and the light receiver in the distance of the prism which stuck the reflecting mirror. It is a schematic diagram which shows the 2 liquid leak sensor (10th Embodiment) which has arrange | positioned the light emission part and the light-receiving part on the same side of the prism which stuck the reflecting mirror. It is sectional drawing which shows an example of the prism which divided | segmented the X surface and Y surface of the prism which stuck the reflecting mirror into plurality. It is a figure explaining the bad effect by the spread of the light which injects into the X surface of the prism which stuck the reflecting mirror. It is sectional drawing of a prism at the time of making it make the X surface of the prism which stuck the reflecting mirror into a curved surface, and preventing the bad effect by the spread of light. It is sectional drawing which shows an example of the conventional optical leak sensor. It is a perspective view showing an example of a conventional optical leak sensor. It is a block diagram which shows an example of the magnetic-type liquid leakage sensor using the conventional magnetic sensor.

Explanation of symbols

1, 13A, 45A, 54A, 61A, 140A, 170A Light emitting unit 3, 20 Prism 4A, 4B, 14A, 16A, 18A, 46A, 55A, 62A, 141A,
171A Light receiving unit 11 Light emission driving unit 12, 96, 123, 162 Light emitter 13, 14, 16, 18, 45, 46, 54, 55, 61, 62, 140, 141,
171 Optical fiber 15, 17, 19, 93, 124, 163 Light receiver 20E, 20E1, 20E2, 20E3 Shield plate 26, 83, 84 Case 30, 92, 122 Detection processing unit 31 Light reception processing unit 32 Alarm unit 40, 63, 70, 100 Tank 42 Lid member 43 Tube 50, 81, 111, 161 Float 51, 65, 82, 112, 160, 172 Holder 60, 85, 114, 115, 131, 150 Reflector 67 Support rod 72, 102 Guide rod 74 Prop 80, 110, 110A Leakage detection unit 82B, 112B Transmission hole 90, 120 Drive control unit 91, 121 Base 95 Half mirror

Claims (34)

A light emitter that is driven by a light emission drive unit to emit light, a first optical fiber that guides the light to the light emission unit, an incident surface on which light from the light emission unit is incident, and light incident from the incident surface is emitted. A prism having an exit surface; first and second light receiving units disposed at two locations for receiving light emitted from the exit surface; and guided from the first light receiver to a second optical fiber. A first light receiver that receives the received light, a second light receiver that receives light guided to the third optical fiber from the second light receiving section, and whether or not light is received in the first light receiver and the second light receiver. Or a light receiving processing unit that detects the amount of received light and determines whether or not there is a leakage of the liquid immersed in the prism and whether or not the leakage is a predetermined liquid;
The first light receiving unit is disposed to receive light emitted from the prism when the prism is immersed in a predetermined liquid,
The second light receiving unit is disposed so as to receive light emitted from the prism when the prism is not immersed in liquid leakage.
The prism is composed of a transparent or translucent hollow member, and the liquid or jelly-like substance and the liquid or the jelly-like substance are sealed in the hollow member. The two-liquid leak sensor according to claim 1, wherein the liquid sealed in the hollow member is water. The two-liquid leak sensor according to claim 1, wherein the liquid sealed in the hollow member is oil. A light emitter that is driven by a light emission drive unit to emit light, a first optical fiber that guides the light to the light emission unit, an incident surface on which light from the light emission unit is incident, and light incident from the incident surface is emitted. A prism having an emission surface; first, second, and third light-receiving units disposed at three locations for receiving light emitted from the emission surface; and second from the first light-receiving unit. A first optical receiver for receiving light guided to the optical fiber; a second optical receiver for receiving light guided from the second light receiving portion to the third optical fiber; and a fourth optical fiber from the third light receiving portion. A third light receiver that receives the light guided to the light source, and the presence or amount of light received in the first light receiver, the second light receiver, and the third light receiver to detect leakage of the prism. A light receiving processing unit for determining the presence of liquid and the type of liquid leakage,
The first light receiving unit is disposed to receive light emitted from the prism when the liquid in which the prism is immersed is oil;
The second light receiving unit is disposed to receive light emitted from the prism when the liquid in which the prism is immersed is water;
The third light receiving unit is disposed so as to receive light emitted from the prism when the prism is not immersed in liquid leakage.
The two-liquid leakage sensor characterized in that the prism is made of a transparent or translucent hollow member, and oil is sealed in the hollow member. A two-liquid leakage sensor for detecting water invading into a tank for storing oil, a light emitter that is driven by a light emission drive unit to emit light, and a first optical fiber that guides the light to the light emission unit A prism having an incident surface on which light from the light emitting unit is incident and an emission surface from which light incident from the incident surface is emitted; and a light receiving unit disposed to receive the light emitted from the emission surface; A light receiver that receives light guided to the second optical fiber from the light receiving unit, and whether the liquid in which the prism is immersed is oil or water depending on whether or not the light is received by the light receiver A light receiving processing unit for determining,
The light emitting unit, the prism and the light receiving unit are arranged in a case, and the case is arranged at the bottom of the tank,
The two-liquid leakage sensor, wherein the prism is formed of a transparent or translucent hollow member, and oil or water is sealed in the hollow member. The two-liquid leak sensor according to claim 5, wherein the case is attached to a cylinder attached to a lid member of the tank, and the case is pressed against the bottom of the tank by the lid member. . A two-liquid leakage sensor for detecting oil entering a tank for storing water, a light emitter that is driven by a light emission drive unit to irradiate light, and a first optical fiber that guides the light to the light emission unit A prism having an incident surface on which light from the light emitting unit is incident and an emission surface from which light incident from the incident surface is emitted; and a light receiving unit disposed to receive the light emitted from the emission surface; A light receiver that receives light guided to the second optical fiber from the light receiving unit, and whether the liquid in which the prism is immersed is oil or water depending on whether or not the light is received by the light receiver A light receiving processing unit for determining,
The prism is made of a transparent or translucent hollow member, and oil or water is sealed in the hollow member,
The light emitting unit, the prism, and the light receiving unit are attached to a float through a holder, and the float is soaked in oil when oil enters the tank. . A light emitter that is driven by a light emission drive unit to emit light, a first optical fiber that guides the light to the light emission unit, an incident surface on which light from the light emission unit is incident, and light incident from the incident surface is emitted. A prism having an exit surface, a reflecting mirror that reflects light emitted from the exit surface, and adjacent to or adjacent to the light emitting unit on the same side as the light emitting unit to receive the light reflected by the reflecting mirror A light receiving unit disposed in the light receiving unit, a light receiving unit configured to receive light guided from the light receiving unit to the second optical fiber, and a liquid in which the prism is immersed depending on whether or not light is received by the light receiving unit. A light receiving processing unit for determining whether or not the liquid is,
The light emitting unit, the prism, the reflecting mirror, and the light receiving unit are configured so that light emitted from the light emitting unit is received by the light receiving unit when the liquid immersed in the prism is a predetermined liquid. Arranged,
The two-liquid leakage sensor, wherein the prism is formed of a transparent or translucent hollow member, and a liquid or jelly-like substance is sealed in the hollow member. In order to shorten the distance from the light emitting unit to the light receiving unit, the light emitting unit is inserted into the prism to prevent the spread of light from the light emitting unit and the harmful effects of light leaking from the first optical fiber. The two-liquid leakage sensor according to claim 1, wherein a shielding plate is provided inside the prism. A two-liquid leakage sensor that detects oil entering a tank that stores water,
A light emitter that is driven by a light emission drive unit and emits light vertically downward;
A mirror disposed at an angle of 45 ° with respect to the horizontal direction to reflect the light emitted from the light emitter and pass through a transmission hole provided in the holder and tilt in the horizontal direction;
A prism having an incident surface on which the light inclined in the horizontal direction is incident and an exit surface from which the light incident from the incident surface is emitted;
A reflecting mirror for reflecting light emitted from the exit surface of the prism;
A light receiver for receiving the light reflected by the reflecting mirror;
A light receiving processing unit that determines whether the liquid in which the prism is immersed is oil or water according to the presence or absence of light reception or the amount of light received by the light receiver;
The holder, the mirror, the prism and the reflecting mirror are attached, and the holder is attached to a float,
The float so that when the oil enters the tank, the prism is immersed in the oil;
The holder is passed through a guide rod so that the holder can only move in the vertical direction and is fixed in the horizontal direction,
The two-liquid leakage sensor, wherein the prism is formed of a transparent or translucent hollow member, and water is sealed in the hollow member. A two-liquid leakage sensor that detects oil entering a tank that stores water,
A light emitter that is driven by a light emission drive unit and emits light vertically downward;
A prism having an incident surface that is irradiated from the light emitter and incident through the transmission hole provided in the holder, and an output surface from which the light incident from the incident surface is emitted;
A reflecting mirror for reflecting light emitted from the exit surface of the prism;
A light receiver for receiving the light reflected by the reflecting mirror;
A light receiving processing unit that determines whether the liquid in which the prism is immersed is oil or water according to the presence or absence of light reception or the amount of light received by the light receiver;
The prism and the reflecting mirror are attached to the holder, and the holder is attached to the float,
The float so that when the oil enters the tank, the prism is immersed in the oil;
The holder is passed through a guide rod so that the holder can only move in the vertical direction and is fixed in the horizontal direction,
The two-liquid leakage sensor, wherein the prism is formed of a transparent or translucent hollow member, and water is sealed in the hollow member. When there is no liquid in the tank and the prism is in contact with air, the light emitted from the light emitter is received by the light receiver as in the case where water is present in the tank. To this end, the two-liquid leakage sensor according to claim 10 or 11, wherein the light emitter is a light emitting diode and a corner cube array is provided around the transmission hole without being sealed in a case. The two-liquid leak sensor according to claim 10 or 11, wherein the light emitter is a laser diode. The two-liquid leakage sensor according to claim 10 or 11, wherein a distance between the light emitter and a bottom surface of the tank is within 3 meters, and the light emitter is a light emitting diode. The two-liquid leak sensor according to any one of claims 8 to 14, wherein the reflecting mirror is a mirror made of stainless steel or the like. The two-liquid leakage sensor according to any one of claims 8 to 14, wherein the reflecting mirror has a corner cube sealed in a transparent or translucent case. The two-liquid leak sensor according to any one of claims 8 to 14, wherein the reflecting mirror has a corner cube array sealed in a transparent or translucent case. The two-liquid leak sensor according to any one of claims 5 to 17, wherein an inclination angle of the inclined surface of the prism is set to 27 ° or less. The two-liquid leak sensor according to any one of claims 1 to 18, wherein the inclined surface is divided so that the shape of the inclined surface side of the section of the prism is a plurality of right triangles. The two-liquid leakage sensor according to any one of claims 1 to 18, wherein the inclined surface is divided so that the shape of the inclined surface side of the section of the prism is a plurality of isosceles triangles. A light shielding plate is provided inside the prism so as to bisect the isosceles triangle from the vertices of a plurality of isosceles triangles in the cross-sectional shape of the prism, and the light is totally reflected by the inclined surface of the prism. 21. The two-liquid leakage sensor according to claim 20, wherein the two-liquid leakage sensor is shielded. The two-liquid leakage according to any one of claims 1 to 21, wherein a shielding plate is provided on a part of an inclined surface of the prism in order to prevent harmful effects caused by spreading of light emitted from the light emitter or the light emitting unit. Liquid sensor. It is a prism made of a transparent or translucent hollow member, and oil is enclosed in the hollow member,
The prism has a quadrilateral ABCD. The quadrilateral ABCD has a ∠A of 70 ° to 75 ° and a ∠B of 90 °, and a plane whose side is the side AB of the prism is an X plane and a side BC. A surface having a cross-section as a Y-plane, a surface having a side AD as a cross-section as a Z-plane, and a reflecting mirror, such as a stainless steel mirror, is disposed on the Y-plane,
A light emitting unit for irradiating light perpendicular to the Z plane;
After the light emitted from the light emitting part is incident on the Z plane, it is incident on either the X plane or the Y plane,
The light incident on the X plane is totally reflected or transmitted by the X plane, and the totally reflected light is reflected by the Y plane and emitted in the normal direction of the Z plane to be received by the light receiving unit. Is supposed to be
The light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected or transmitted by the X plane, and the totally reflected light is emitted in the normal direction of the Z plane. And is received by the light receiving unit,
The light emitting unit emits light emitted from a light emitter driven by a light emission driving unit and guided by a first optical fiber,
The light received by the light receiving unit is guided by the second optical fiber and received by the light receiver,
The two-liquid leakage sensor, wherein the light receiving processing unit determines whether the liquid immersed in the prism is oil or water based on the presence or absence of light received by the light receiver or the amount of light received. It is a prism made of a transparent or translucent hollow member, and oil is enclosed in the hollow member,
The prism has a quadrilateral ABCD. The quadrilateral ABCD has a ∠A of 70 ° to 75 ° and a ∠B of 90 °, and a plane whose side is the side AB of the prism is an X plane and a side BC. A surface having a cross-section as a Y-plane, a surface having a side AD as a cross-section as a Z-plane, and a reflecting mirror, such as a stainless steel mirror, is disposed on the Y-plane,
Comprising a light emitter driven by a light emission driving unit for irradiating light perpendicularly incident on the Z plane;
The light emitted from the light emitter enters the Z plane, and then enters either the X plane or the Y plane.
The light incident on the X plane is totally reflected or transmitted by the X plane, and the totally reflected light is reflected by the Y plane and emitted in the normal direction of the Z plane to be received by a light receiver. Is supposed to be
The light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected or transmitted by the X plane, and the totally reflected light is emitted in the normal direction of the Z plane. And is received by the receiver.
The two-liquid leakage sensor, wherein the light receiving processing unit determines whether the liquid immersed in the prism is oil or water based on the presence or absence of light received by the light receiver or the amount of light received. It is a prism made of a transparent or translucent hollow member, and oil is enclosed in the hollow member,
The prism includes a Z plane that allows light to enter from a normal direction, an X plane that is divided into a plurality of portions inclined by 70 ° to 75 ° with respect to the Z plane, and the prism adjacent to the X plane. A plurality of divided Y planes inclined at 90 ° to the X plane,
A reflection mirror, which is a mirror made of stainless steel or the like, is disposed on the Y surface, and includes a light emitting unit that irradiates light that enters the Z surface of the prism perpendicularly,
After the light emitted from the light emitting part is incident on the Z plane, it is incident on either the X plane or the Y plane,
The light incident on the X plane is totally reflected or transmitted by the X plane, and the totally reflected light is reflected by the Y plane and emitted in the normal direction of the Z plane to be received by the light receiving unit. Is supposed to be
The light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected or transmitted by the X plane, and the totally reflected light is emitted in the normal direction of the Z plane. And is received by the light receiving unit,
The light emitting unit emits light emitted from a light emitter driven by a light emission driving unit and guided by a first optical fiber,
The light received by the light receiving unit is guided by the second optical fiber and received by the light receiver,
The two-liquid leakage sensor, wherein the light receiving processing unit determines whether the liquid immersed in the prism is oil or water based on the presence or absence of light received by the light receiver or the amount of light received. It is a prism made of a transparent or translucent hollow member, and oil is enclosed in the hollow member,
The prism includes a Z plane that allows light to enter from a normal direction, an X plane that is divided into a plurality of portions inclined by 70 ° to 75 ° with respect to the Z plane, and the prism adjacent to the X plane. A plurality of divided Y planes inclined at 90 ° to the X plane,
A reflecting mirror which is a mirror made of stainless steel or the like is disposed on the Y surface,
A light emitter driven by a light emission driving unit that irradiates light perpendicularly incident on the Z-plane of the prism;
The light emitted from the light emitter enters the Z plane, and then enters either the X plane or the Y plane.
The light incident on the X plane is totally reflected or transmitted by the X plane, and the totally reflected light is reflected by the Y plane and emitted in the normal direction of the Z plane to be received by a light receiver. Is supposed to be
The light incident on the Y plane is reflected by the Y plane, and the reflected light is totally reflected or transmitted by the X plane, and the totally reflected light is emitted in the normal direction of the Z plane. And is received by the receiver.
The two-liquid leakage sensor, wherein the light receiving processing unit determines whether the liquid immersed in the prism is oil or water based on the presence or absence of light received by the light receiver or the amount of light received. A transparent or translucent hollow member having an inclined surface, comprising a liquid or a jelly-like substance enclosed in the hollow member, an inlet for injecting the liquid or the jelly-like substance, and a plug of the inlet A prism for a two-liquid leak sensor, characterized in that an air or vacuum gap is provided between the stopper and the liquid or jelly-like substance. The prism for a two-liquid leak sensor according to claim 27, wherein an inclination angle of the inclined surface is set to 27 ° or less. 29. The prism for a two-liquid leak sensor according to claim 27 or 28, wherein the inclined surface is divided so that the shape of the inclined surface side of the section of the prism is a plurality of right triangles. 29. The prism for a two-liquid leak sensor according to claim 27 or 28, wherein the inclined surface is divided so that the shape of the inclined surface side of the cross section of the prism is a plurality of isosceles triangles. A light shielding plate is provided inside the prism so as to bisect the isosceles triangle from the vertices of a plurality of isosceles triangles in the cross-sectional shape of the prism, and the light is totally reflected by the inclined surface of the prism. The prism for a two-liquid leak sensor according to claim 30, wherein the prism is shielded. 32. The two-liquid-leak sensor prism according to claim 27, wherein a shielding plate is provided on a part of the inclined surface of the prism in order to prevent harmful effects caused by spreading of light. A transparent or translucent hollow member, a liquid sealed in the hollow member, an inlet for injecting the liquid, and a stopper for the inlet, and air or vacuum between the stopper and the liquid. A two-liquid leakage sensor prism in which a gap portion is provided,
The cross-sectional shape of the prism is a square ABCD. The square ABCD has a ridge A of 70 ° to 75 ° and a ridge B of 90 °, and a reflecting mirror is disposed on a surface having the side BC of the prism as a cross section. A prism for a two-liquid leakage sensor, wherein A transparent or translucent hollow member, a liquid sealed in the hollow member, an inlet for injecting the liquid, and a stopper for the inlet, and air or vacuum between the stopper and the liquid. A two-liquid leakage sensor prism in which a gap portion is provided,
The prism includes a Z plane that allows light to enter from a normal direction, an X plane that is divided into a plurality of portions inclined by 70 ° to 75 ° with respect to the Z plane, and the prism adjacent to the X plane. A prism for a two-liquid leak sensor, comprising a plurality of divided Y surfaces inclined by 90 ° on the X surface, and a reflecting mirror disposed on the Y surface.

Images